There is a constantly increasing need for sunscreen protection agents in a population that is exposed to an increasing amount of damaging sunlight. Repetitive sun exposure can result in skin changes known as photoaged skin. The clinical changes that are seen in photoaged skin differ from those of normally aged skin in sunlight protected sites of the body. Among the damaging results of intensive sun exposure of the skin there is increased wrinkling, elastosis, pigmentary changes, precancerous and cancerous skin lesions.
Many sunscreening chemicals have been developed in the past protecting against the harmful effect of UV-A (320 to 400 nm) and/or UV-B (290-320 nm) wavelength and even shorter wavelength (UV-C). These chemicals are usually incorporated either alone or in combination with each other into cosmetic or pharmaceutical preparations which are widely known and used.